Gameplay characters are NOT primarily identified through classes. The Active ability is the strongest gameplay design anchor. The sprite communicates the Active through weapon/device silhouette, pose, clothing appropriate to its use, and property colour where relevant.
Example: a FIRE Active does not require a fantasy mage. It may use a human engineer or fighter + a large Tower-tech combustion projector + orange/red active material. The gameplay read is LARGE DEVICE + ORANGE = FIRE.
Amended D-311 It may also be a fantasy mage: robes, a hat, and a classic staff that is the device. What must read is still the device and its property colour; the staff's head is where the hot stone sits. Glowing runes stay banned.
Amended D-080 There is one gameplay sprite per Active. Everyone who carries that Active wears it in combat, with at most a palette tint to tell two of them apart.